David Gems in American Scientist:
The 20th century brought both profound suffering and profound relief to people around the world. On the one hand, it produced political lunacy, war and mass murder on an unprecedented scale. But there were also extraordinary gains—not least in public health, medicine and food production. In the developed world, we no longer live in constant fear of infectious disease. Furthermore, a Malthusian catastrophe of global population growth exceeding food production—a terrifying prospect predicted first in the 18th century—did not materialize. This is largely due to a steep decline in birth rates, for which we can thank the education, emancipation and rationality of women. Most people in the developed world can now expect to live long lives.
Yet, as too often happens, the solution of one problem spawns others. Because we are having fewer children and living longer, the developed world is now filling up with old people. In Japan, for example, where the population is aging particularly quickly, the ratio of people less than 20 years old to those over 65 is plummeting, from 9.3 in 1950 to a predicted 0.59 in 2025. In Europe and the United States, we see ever more bald and grey heads on streets and in parks and shopping malls. Although this is something to celebrate, old age unfortunately has myriad ways of making us ill. It brings cardiovascular disease that leads to heart attacks and strokes; neurodegenerative diseases such as Alzheimer’s and Parkinson’s that erode the self; and macular degeneration, which blinds. And, of course, there is cancer. Aging has been described as the greatest of all carcinogens.
More here.